Exodus 19:21-25

And the LORD said to Moses, “Go down and warn the people, lest they break through to the LORD to look and many of them perish. Also let the priests who come near to the LORD consecrate themselves, lest the LORD break out against them.” And Moses said to the LORD, “The people cannot come up to Mount Sinai, for you yourself warned us, saying, ‘Set limits around the mountain and consecrate it.’” And the LORD said to him, “Go down, and come up bringing Aaron with you. But do not let the priests and the people break through to come up to the LORD, lest he break out against them.” So Moses went down to the people and told them.